I recently purchased a home that is equipped with a Trane XR80. When we first started running the heat, the blower was very strong. It's been about a month or two. All of a sudden, the other day, the force of the air seemed about 60-70% weaker than what we were used to. There is only one large register and the only return is in the basement at the bottom of the unit.
Any advice would be helpful. This is my first winter as a home owner and my first experience with a forced air furnace. Thank you in advance for any advice.